1. Field of the Invention
The present invention relates to an adjustable, self-leveling bed frame useful for installation in the sleeper compartments of truck tractors.
2. Description of the Prior Art
Across the United States of American, as well as other nations, much of the goods of commerce are transported by trucking rigs called semi-tractor trailers. These trucking rigs are comprised of a combination of an enclosed un-powered trailer, with one or more rear axles and a forward hitch, and a powered, tractor occupied by the driver and other passengers which pulls the trailer across the roadway. These semi-tractor trailer rigs are capable of hauling up to 20 tons of cargo for long distances over a nation's roads and highways.
During long-distance haulage, drivers often have difficulty finding sleeping facilities. To this end, many tractor cabs are equipped with sleeper compartments with a built-in bed frame and mattress, allowing the driver to sleep within the cab. The bed frame is typically mounted transversely and located behind the driver's and passenger's seats. This sleeper compartment can be conveniently used by a driver after parking the rig at a rest stop, many of which have been constructed on the interstate highway system. But, in the vast undeveloped expanses of the American West, rest stops or adequate hotel or motel facilities may be hundreds of miles apart, often necessitating a driver to pull off roadway to rest and sleep instead of risking the potential hazard of falling asleep during the hours needed to reach the next location for comfortable sleep. However, highways and roadways are typically constructed with a crown, in which the roadway, in lateral cross-section, is highest in the middle and slopes downward towards either shoulder or side. This crown, along with any slope in the roadway, places the cot at an angle from horizontal, which for many people interferes with a restful sleep.
Alternatively, these semi-tractor trailers equipped with sleeper compartments may be driven by a team of two drivers, who alternate in driving the rig. While one is driving the other is resting or sleeping. This scheme permits the rig to operate nearly continuously, thereby reducing overall shipping time and labor costs. While operating in this manner, one driver would drive the rig, and the other would sleep, either in the passenger seat or in the sleeper compartment, if so provided. However, the vibrations as well as the slope and crown of the roadway interfere with a restful sleep.
A bed frame is desirable which can mount within a sleeper compartment of a semi-tractor trailer rig, which can absorb road vibration and can adjust for the pitch and roll from the slope and crown of the roadway. Several attempts have been made in the prior art to address these problems. For example, Davis, U.S. Pat. No. 6,671,900, teaches of a bed leveler/adjuster which provides a bed frame which is comprised of two end sections which pivot at a middle section. The middle section may be vertically elevated, and either end section can be pivoted relative to the middle section. This provides a means for inclining the bed frame, either at the foot or at the head, to compensate for lateral cant in a tractor parked on the shoulder or edge of a road. The head or foot of the frame may be further inclined relative to the other frame section to provide for more comfort. However, it cannot compensate for any longitudinal pitch of the cab when the rig is parked on a sloped roadway. Under such circumstances, a person using a bed frame as taught in Davis might still experience discomfort from rolling, or the sensation of rolling, out of the bed frame.
In Renggli et al., U.S. Pat. No. 4,625,348, a mechanism for inclining a bed frame is disclosed. However, the entire frame remains in a constant plane, the head or foot ends cannot be inclined relative to the other end for further comfort. In addition, it cannot be canted laterally.
Anderson et al., U.S. Pat. No. 4,144,601; Dome, U.S. Pat. No. 3,299,447, Vogel et al., U.S. Pat. No. 4,497,078; Zach et al., U.S. Pat. No. 3,760,436 and Lefler et al., U.S. Pat. No. 4,196,483, all teach of bed frames for a tractor cab which provide means for isolating the bed frame from road vibration, but which do not provide any means for longitudinally inclining or laterally canting the frame to compensate for crown or slope in the roadway. The inventions disclosed in these patents are uniquely suited only for berthing while the tractor cab is in motion, and would not provide needed comfort when the cab was parked on the shoulder of a roadway.
A sleeper bed frame which can mount in a sleeper section of a tractor cab and which can be inclined longitudinally and canted laterally, which isolates roadway vibration and which has an end section which can be further tilted relative to the other end section is desirable.